0000000000991895
AUTHOR
F. Aceti
showing 22 related works from this author
The $K \bar K \pi$ decay of the $f_1(1285)$ and its nature as a $K^* \bar K -cc$ molecule
2015
We investigate the decay of $f_1(1285) \to \pi K \bar K$ with the assumption that the $f_1(1285)$ is dynamically generated from the $K^* \bar{K} - cc$ interaction. In addition to the tree level diagrams that proceed via $f_1(1285) \to K^* \bar{K} - cc \to \pi K \bar K$, we take into account also the final state interactions of $K \bar K \to K \bar K$ and $\pi K \to \pi K$. The partial decay width and mass distributions of $f_1(1285) \to \pi K \bar K$ are evaluated. We get a value for the partial decay width which, within errors, is in fair agreement with the experimental result. The contribution from the tree level diagrams is dominant, but the final state interactions have effects in the m…
Isospin breaking andf0(980)-a0(980) mixing in theη(1405) →π0f0(980) reaction
2014
We make a theoretical study of the η (1405) → π 0 f 0 (980) and η (1405) → π 0 a 0 (980) reactions to determine the isospin violation and the mixing of the f 0 (980) and a 0 (980) resonances. We make use of the chiral unitary approach where these two resonances appear as dynamically generated by the meson-meson interaction provided by chiral Lagrangians. We obtain a very narrow shape for the f 0 (980) production in agreement with a BES experiment. As to the amount of isospin violation, assuming constant vertices for the primary η (1405) → π 0 K K and η (1405) → π 0 π 0 η production, we find results which are much smaller than found in the experimental BES paper. The problem is solved by usi…
Study of theZb(10610) andZb(10650) states through $B\bar{B}^*$ and $B^*\bar{B}^*$ interactions using local hidden gauge approach
2016
We have studied the $B\bar{B}^*$ and $B^*\bar{B}^*$ interactions for isospin I = 1 using the Local Hidden gauge approach. Since both interactions via one light meson exchange are not allowed by Okubo-Zweig-Iizuka (OZI) rule, we investigated the contributions for those interactions coming from two pions, interacting and noninteracting among themselves, and also due to the heavy vector meson exchange, in which the OZI rule no longer holds. From the amplitudes calculated by these mechanism, we determine an effective potential which is used as a kernel of the Bethe-Salpeter equation. Our goal is look for poles in the T-matrix in attemp to relate them with the charged Zb (10610) and Zb (10650) s…
Wave functions of composite hadron states and relationship to couplings of scattering amplitudes for general partial waves
2012
In this paper we present the connection between scattering amplitudes in momentum space and wave functions in coordinate space, generalizing previous work done for $s$-waves to any partial wave. The relationship to the wave function of the residues of the scattering amplitudes at the pole of bound states or resonances is investigated in detail. A sum rule obtained for the couplings provides a generalization to coupled channels, any partial wave and bound or resonance states, of Weinberg's compositeness condition, which was only valid for weakly bound states in one channel and $s$-wave. An example, requiring only experimental data, is shown for the $\ensuremath{\rho}$ meson indicating that i…
Discussion on triangle singularities in the Λb→J/ψK−p reaction
2016
We have analyzed the singularities of a triangle loop integral in detail and derived a formula for an easy evaluation of the triangle singularity on the physical boundary. It is applied to the ${\mathrm{\ensuremath{\Lambda}}}_{b}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{\ensuremath{-}}p$ process via ${\mathrm{\ensuremath{\Lambda}}}^{*}$-charmonium-proton intermediate states. Although the evaluation of absolute rates is not possible, we identify the ${\ensuremath{\chi}}_{c1}$ and the $\ensuremath{\psi}(2S)$ as the relatively most relevant states among all possible charmonia up to the $\ensuremath{\psi}(2S)$. The $\mathrm{\ensuremath{\Lambda}}(1890){\ensuremath{\chi}}_{c1}p$ loop is ver…
Prediction of a $Z_c(4000)$ $D^* \bar D^*$ state and relationship to the claimed $Z_c(4025)$
2014
After discussing the OZI suppression of one light meson exchange in the interaction of $D^* \bar D^*$ with isospin I=1, we study the contribution of two pion exchange to the interaction and the exchange of a heavy vector $J/\psi$. We find this latter mechanism weak but enough to barely bind the system in J=2 with a mass around 4000 MeV, while the effect of the two pion exchange is a net attraction but weaker than that from $J/\psi$ exchange. We discuss this state and try to relate it to the $Z_c(4025)$ state, above the $D^* \bar D^*$ threshold, claimed in an experiment at BES from and enhancement of the $D^* \bar D^*$ distribution close to threshold. Together with the results from a recent …
$f_1(1285)$ decays into $a_0(980)\pi^0$, $f_0(980)\pi^0$ and isospin breaking
2015
We evaluate the decay width for the processes $f_1(1285) \to \pi^0 a_0(980)$ and $f_1(1285) \to \pi^0 f_0(980)$ taking into account that all three resonances are dynamically generated from the meson-meson interaction, the $f_1(1285)$ from $K^* \bar K -c.c$ and the $a_0(980)$, $f_0(980)$ from $\pi \eta, K \bar K$ and $\pi \pi, K \bar K$ respectively. We use a triangular mechanism similar to that of the $\eta(1405) \to \pi \pi \eta$, which provides a decay width for $f_1(1285) \to \pi^0 a_0(980)$ with a branching fraction of the order of 30%, in agreement with experiment. At the same time we evaluate the decay width for the isospin forbidden $f_1(1285) \to \pi^0 f_0(980)$, which appears when …
Isospin breaking andf0(980)-a0(980)mixing in theη(1405)→π0f0(980)reaction
2012
We make a theoretical study of the eta(1405) -> pi(0)f(0)(980) and eta(1405) -> pi(0)a(0)(980) reactions with an aim to determine the isospin violation and the mixing of the f(0)(980) and a(0)(980) resonances. We make use of the chiral unitary approach where these two resonances appear as composite states of two mesons, dynamically generated by the meson-meson interaction provided by chiral Lagrangians. We obtain a very narrow shape for the f(0)(980) production in agreement with a BES experiment. As to the amount of isospin violation, or f(0)(980) and a(0)(980) mixing, assuming constant vertices for the primary eta(1405) -> pi K-0 (K) over bar and eta(1405) -> pi(0)pi(0)eta production, we f…
Prediction of anI=1DD¯*state and relationship to the claimedZc(3900),Zc(3885)
2014
We study here the interaction of $D{\overline{D}}^{*}$ in the isospin $I=1$ channel in light of recent theoretical advances that allow us to combine elements of the local hidden gauge approach with heavy quark spin symmetry. We find that the exchange of light $q\overline{q}$ is Okubo-Zweig-Iizuka (OZI) suppressed and thus we concentrate on the exchange of heavy vectors and of two pion exchange. The latter is found to be small compared to the exchange of heavy vectors, which then determines the strength of the interaction. A barely $D{\overline{D}}^{*}$ bound state decaying into ${\ensuremath{\eta}}_{c}\ensuremath{\rho}$ and $\ensuremath{\pi}J/\ensuremath{\psi}$ is found. At the same time we…
The KK¯π decay of the f1(1285) and its nature as a K⁎K¯−cc molecule
2015
AbstractWe investigate the decay of f1(1285)→πKK¯ with the assumption that the f1(1285) is dynamically generated from the K⁎K¯−cc interaction. In addition to the tree level diagrams that proceed via f1(1285)→K⁎K¯−cc→πKK¯, we take into account also the final state interactions of KK¯→KK¯ and πK→πK. The partial decay width and mass distributions of f1(1285)→πKK¯ are evaluated. We get a value for the partial decay width which, within errors, is in fair agreement with the experimental result. The contribution from the tree level diagrams is dominant, but the final state interactions have effects in the mass distributions. The predicted mass distributions are significantly different from phase s…
f1(1285) decays into a0(980)π0, f0(980)π0 and isospin breaking
2016
We evaluate the decay width for the processes f1(1285) → π0a0(980) and f1(1285) → π0f0(980) taking into account that all three resonances are dynamically generated from the meson-meson interaction, the f1(1285) from K*K¯+cc and the a0 (980), f0(980) from πη, KK¯ and ππ, KK¯ respectively. We use a triangular mechanism similar to that of the η(1405)→ππη, which provides a decay width for f1 (1285) → π0a0 (980) with a branching fraction of the order of 30%, in agreement with experiment. At the same time we evaluate the decay width for the isospin forbidden f1(1285) → π0 f0(980), which appears when we consider different masses for the charged and neutral kaons, and show that it is much more supp…
X(3872)→J/ψγdecay in theDD¯*molecular picture
2012
From a picture of the X(3872) where the resonance is a bound state of $\bar{D}D^*-c.c.$, we evaluate the decay width into the $J/\psi \gamma$ channel, which is sensitive to the internal structure of this state. For this purpose we evaluate the loops through which the X(3872) decays into its components, and the $J/\psi$ and the photon are radiated from these components. We use the local hidden gauge approach extrapolated to SU(4) with a particular SU(4) breaking. The radiative decay involves anomalous couplings and we obtain acceptable values which are compared to experiments and results of other calculations. Simultaneusly, we evaluate the decay rate for the X(3872) into $J/\psi \omega$ and…
a1(1420) peak as the πf0(980) decay mode of the a1(1260)
2016
We study the decay mode of the ${a}_{1}(1260)$ into a ${\ensuremath{\pi}}^{+}$ in $p$ wave and the ${f}_{0}(980)$ that decays into ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ in $s$ wave. The mechanism proceeds via a triangular mechanism where the ${a}_{1}(1260)$ decays into ${K}^{*}\overline{K}$, the ${K}^{*}$ decays to an external ${\ensuremath{\pi}}^{+}$ and an internal $K$ that fuses with the $\overline{K}$ producing the ${f}_{0}(980)$ resonance. The mechanism develops a singularity at a mass of the ${a}_{1}(1260)$ around 1420 MeV, producing a peak in the cross section of the $\ensuremath{\pi}p$ reaction, used to generate the mesonic final state, which provides a natural…
The KK¯π decay of the f1(1285) and its nature as a K*K¯ − cc molecule
2016
We investigate the decay of f1(1285)→πKK¯ with the assumption that the f1(1285) is dynamically generated from the K*K¯+cc interaction. In addition to the tree level diagrams that proceed via f1(1285)→K*K+cc→πKK¯, we take into account also the final state interactions of KK¯→KK¯ and πK → πK. The partial decay width and mass distributions of f1(1285)→πKK¯ are evaluated. We get a value for the partial decay width which, within errors, is in fair agreement with the experimental result. The contribution from the tree level diagrams is dominant, but the final state interactions have effects in the mass distributions. The predicted mass distributions are significantly different from phase space an…
Meson baryon components in the states of the baryon decuplet
2013
We apply an extension of the Weinberg compositeness condition on partial waves of $L=1$ and resonant states to determine the weight of meson-baryon component in the $\Delta(1232)$ resonance and the other members of the $J^P= \frac{3}{2}^+$ baryon decuplet. We obtain an appreciable weight of $\pi N$ in the $\Delta(1232)$ wave function, of the order of 60 \%, which looks more natural when one recalls that experiments on deep inelastic and Drell Yan give a fraction of $\pi N$ component of 34 \% for the nucleon. We also show that, as we go to higher energies in the members of the decuplet, the weights of meson-baryon component decrease and they already show a dominant part for a genuine, non me…
The KK¯π decay of the f1(1285) and its nature as a K⁎K¯−cc molecule
2015
Abstract We investigate the decay of f 1 ( 1285 ) → π K K ¯ with the assumption that the f 1 ( 1285 ) is dynamically generated from the K ⁎ K ¯ − c c interaction. In addition to the tree level diagrams that proceed via f 1 ( 1285 ) → K ⁎ K ¯ − c c → π K K ¯ , we take into account also the final state interactions of K K ¯ → K K ¯ and π K → π K . The partial decay width and mass distributions of f 1 ( 1285 ) → π K K ¯ are evaluated. We get a value for the partial decay width which, within errors, is in fair agreement with the experimental result. The contribution from the tree level diagrams is dominant, but the final state interactions have effects in the mass distributions. The predicted m…
Meson-baryon components in the states of the baryon decuplet
2014
We apply an extension of the Weinberg compositeness condition on partial waves of L = 1 and resonant states to determine the weight of the meson-baryon component in the Delta(1232) resonance and the other members of the baryon decuplet. We obtain an appreciable weight of pi N in the Delta(1232) wave function, of the order of 60%, which looks more natural when one recalls that experiments on deep inelastic and Drell Yan give a fraction of pi N component of 34% for the nucleon. We also show that, as we go to higher energies in the members of the decuplet, the weights of the meson-baryon component decrease and they already show a dominant part for a genuine, non-meson-baryon, component in the …
The small K pi component in the K* wave functions
2013
We use a recently developed formalism which generalizes Weinberg's compositeness condition to partial waves higher than s-wave in order to determine the probability of having a K pi component in the K* wave function. A fit is made to the K pi phase shifts in p-wave, from where the coupling of K* to K pi and the K pi loop function are determined. These ingredients allow us to determine that the K* is a genuine state, different from a K pi component, in a proportion of about 80%.
Study ofBB¯*andB*B¯*interactions inI=1and relationship to theZb(10610),Zb(10650)states
2015
We use the local hidden gauge approach in order to study the $B{\overline{B}}^{*}$ and ${B}^{*}{\overline{B}}^{*}$ interactions for isospin $I=1$. We show that both interactions via one light meson exchange are not allowed by the Okubo-Zweig-Iizuka rule and, for that reason, we calculate the contributions due to the exchange of two pions, interacting and noninteracting among themselves, and also due to the heavy vector mesons. Then, to compare all these contributions, we use the potential related to the heavy vector exchange as an effective potential corrected by a factor which takes into account the contribution of the other light meson exchanges. In order to look for poles, this effective…
The $K \bar K ��$ decay of the $f_1(1285)$ and its nature as a $K^* \bar K -cc$ molecule
2015
We investigate the decay of $f_1(1285) \to ��K \bar K$ with the assumption that the $f_1(1285)$ is dynamically generated from the $K^* \bar{K} - cc$ interaction. In addition to the tree level diagrams that proceed via $f_1(1285) \to K^* \bar{K} - cc \to ��K \bar K$, we take into account also the final state interactions of $K \bar K \to K \bar K$ and $��K \to ��K$. The partial decay width and mass distributions of $f_1(1285) \to ��K \bar K$ are evaluated. We get a value for the partial decay width which, within errors, is in fair agreement with the experimental result. The contribution from the tree level diagrams is dominant, but the final state interactions have effects in the mass distri…
Prediction of an $I=1$ $D \bar D^*$ state and relationship to the claimed $Z_c(3900)$, $Z_c(3885)$
2014
We study here the interaction of $D \bar D^*$ in the isospin $I=1$ channel in the light of recent theoretical advances that allow to combine elements of the local hidden gauge approach with heavy quark spin symmetry. We find that the exchange of light $q \bar q$ is OZI suppressed and, thus, we concentrate on the exchange of heavy vectors and of two pion exchange. The latter is found to be small compared to the exchange of heavy vectors, which then determines the strength of the interaction. A barely $D\bar{D}^*$ bound state decaying into $\eta_c\rho$ and $\pi J/\psi$ is found. At the same time we reanalyze the data of the BESIII experiment on $e^+ e^- \to \pi^{\pm} (D \bar D^*)^\mp$, from w…
Study of $B\bar{B}^*$ and $B^*\bar{B}^*$ interactions in $I=1$ and relationship to the $Z_b(10610)$, $Z_b(10650)$ states
2014
We use the local hidden gauge approach in order to study the $B\bar{B}^*$ and $B^*\bar{B}^*$ interactions for isospin I=1. We show that both interactions via one light meson exchange are not allowed by OZI rule and, for that reason, we calculate the contributions due to the exchange of two pions, interacting and noninteracting among themselves, and also due to the heavy vector mesons. Then, to compare all these contributions, we use the potential related to the heavy vector exchange as an effective potential corrected by a factor which takes into account the contribution of the others light mesons exchange. In order to look for poles, this effective potential is used as the kernel of the Be…